Field of the Invention
The present invention relates to a lamination molding apparatus.
Background of the Invention
In a lamination molding method using laser beam, a very thin material powder layer is formed on a molding table capable of moving vertically, followed by irradiation of a predetermined position of the material powder layer with a laser beam, thereby sintering the material powder. These procedures are repeated to attain the desired three-dimensional shape of a sintered object integrally formed by laminating a plurality of sintered layers. If necessary, while molding of the object, cutting may be applied to the surface or unnecessary portion of the sintered object obtained by sintering the material powder, using a rotary cutting tool capable of moving horizontally and vertically such as an end mill or the like. Over the combination and repetition of these steps, a desired molded object is formed.
In the laser molding method using the laser beam, in order to prevent alteration of the material powder and allow stable irradiation of the laser beam with required energy at all times, a sealed chamber is filled with inert gas, so that the laser beam can be emitted to a predetermined irradiation region in an atmosphere with a sufficiently low oxygen concentration in the chamber. Also, when sintering by irradiating the material powder with the laser beam, specific smoke called fume is generated. When the chamber is filled with the fume, the laser beam is blocked by the fume and the laser beam with the required energy to sinter does not reach the irradiation position substantially, and thereby an inferior sintering may occur. Then, the lamination molding apparatus configured to supply clean inert gas into the chamber and to discharge the inert gas containing fumes from the chamber, is known.
Here, the lamination molding apparatus using the method of selective laser sintering disclosed in Patent Document 1 comprises a recoater head that moves in a horizontal one axis direction. The recoater head forms a material powder layer in a desired region on a molding table by free-falling the material powder contained therein from the powder supply port and planarizing the material powder.